HOW TO HAVE A CLEAN OUTPUT WITH RUBY DEBUG?

Hello, after configuring my simple logstash.conf with input stdin and output stdout, I always get a duty output with

input :
dhschggdsgg

output :
{
"host"←[0;37m => ←[0m←[0;33m"hostname"←[0m,
"message"←[0;37m => ←[0m←[0;33m"dhschggdsgg \r"←[0m,
"@version"←[0;37m => ←[0m←[0;33m"1"←[0m,
"@timestamp"←[0;37m => ←[0m2019-07-29T13:14:51.086Z
}

logstash.conf

input {
stdin {
}
}

output {
stdout{
codec => rubydebug
}
}

I just want to have something as output clean without [0;37m .. everywhere

can someone help me please ?